Nanao MS9-29 several boards t/s

Hello friends,

I have a few boards i plan on working on with some issues. Many of them similar. I have already done the cap kit change on most of these. I had worked on these before, but plan on coming back soon. Just gathering things i might need first before i start. I plan to update the thread of my progress. I used a search engine to get me started and got the ai response, which might have some good directions to start.

The most common issue on the first few boards are a missing color. RGB driver transistor Q302/Q312/Q322 I think these are NEC 2SC4001. I was able to find some on ebay but not sure if they were correct. I also found these on Amazon. They are cheaper than the ones i got on eBay (comes to $2 each), but uncertain if they are any good. I know with components, they get updated so sometimes might have different numbers.

https://www.amazon.com/Slice-Transistor-2SA1546-2SC4001-A1546/dp/B0D8JGNJW7

After that, here are some of the other suggestions.
Check the gain/cutoff pots.
Inspect the ribbon cable / wire harness.
Check the associated zener diodes (ZD301/ZD311/ZD321) and resistors (R306/R316/R326).
Check the LA7837/LA7853 video IC on the main board.

I would also suggest checking the M51387P if colors are weak/dead on the MS9.

IPD said:

I would also suggest checking the M51387P if colors are weak/dead on the MS9.

Click to expand...

I saw that being posted in another forum. It did end up being what was wrong in that situation. I have taken the opportunity to order some from ebay so hopefully when it gets here in the middle of next week.